Machine for making foundry cores and molds



y 1951 H. s. HERBRUGGEN 2,553,946

MACHINE FOR MAKING FOUNDRY CORES AND MOLDS Filed Jan. 24, 1949 5Sheets-Sheet l N VEN 7'0}? HEM/RICH SCHULTE HEABRwQBv HHOPHEYS May 22,1951 H. s. HERBRU'GGEN 2,553,946

MACHINE FOR MAKING FOUNDRY CORES AND MOLDS Filed Jan. 24, 1949 5Sheets-Sheet 2 May 22, 1951 H. s. HERBRUGGEN 2,553,946

MACHINE FOR MAKING FOUNDRY CORES AND MOLDS Filed Jan. 24, 1949 5Sheets-Sheet 5 MNENTOR l/E/A/R/C say ULTE" HERBRUGQEA/ RTT R NEVS y 22,1951 H. s. HERBRUGGEN 2,553,946

MACHINE FOR MAKING FOUNDRY CORES AND MOLDS Filed Jan. 24, 1949 5Sheets-Sheet 4 HTTOKNEYS y 1951 H s. HERBRUGGEN 2,553,946

MACHINE FOR MAKING FOUNDRY CORES AND MOLDS Filed Jan. 24, 1949 5Sheets-Sheet 5 INVENTOI? HEM/ m so /om? flRBRucae/v 3y rpm 6cmHTTOA/VEYS Patented May 22, 1951 MACHENE FOR MAKING FOUNDRY CORES ANDMOLDS Heinrich Schulte Herbruggen,

Hagen-Kalle],

Germany, assignor to The Constructional Engineering Company Limited,Birmingham, v England, a company of Great Britain Application January24, 1949, Serial No. 72,460

In Great Britain March 11, 1948 4 Claims.

This invention relates to improvements in machines for making foundrycores and moulds and refers particularly to machines or the type inwhich prepared sand is fed from a hopper or the like into a chamber fromwhich it is forced by air under pressure through openings in the bottomof the chamber into a core box or moulding box which is supported on atable movable vertically by hydraulic or pneumatic means to hold thecore box or moulding box against the blowing chamber for filling. Amachine of this type is described in the specification of British PatentNo. 570,193.

According to my invention a machine of the type set forth abovecomprises an intermittently rotated sand container, an intermittentlyoperated shutter controlling the delivery of sand from the container toa blOWillg chamber, a table for supporting a core-box or mould to befilled, means for moving the table vertically to clamp the core box ormould against the bottom of the blowing chamber, pneumatic means forintensifying the clamping pressure on the core box or mould duringfilling, and a rotary control for controlling each of the operations ormovements and for ensuring automatically that they take place in thecorrect sequence.

The control may be operated by hand or it may be operated by an electricmotor with a pushbutton switch so that the machine is completelyautomatic and the operator has simply to place the core-boxes or mouldson the table and remove them at the appropriate times in the sequencesof operations. 7

One practical form of machine for making foundry cores or moulds inaccordance with my invention is illustrated. by way of example in theaccompanying drawings in which- Figure 1 is a front elevation of thecomplete machine.

Figure 2 is a plan.

Figure 3 is a side elevation.

Figure 4 is an elevation on a larger scale and partly in section of thelower end of the machine showing the means for operating the ram andapplying pressure to the core-box.

Figure 5 is a sectional elevation of the control mechanism for themachine.

Figure 6 is a horizontal section of the control mechanism.

In the machine illustrated the mainpart of the supporting frame consistsof two rigid vertical columns IE, il. Mounted on the upper end of theframe at one side is the sand container 12 which is a cylindricalchamber mounted for ro- 2 tation about a vertical axis and divided byradial partitions ['3 into, say, six segmental compartments. Thecontainer is adapted to be rotated intermittently through a chain It andtoothed ring l5 by an electric motor 36. The container is open at thebottom but is in contact with a circular plate ll having an opening I 8leading into the blowing chamber I9. The opening I8 is controlled by anangularly movable shutter 29 operated by a pneumatic cylinder 2 I.

The blowing chamber is of the known type described in British patentspecification No. 570,193 with means for supplying air under pressure toan air belt around the chamber, a wire gauze or like screen on the innerside of the airbelt, and a power driven agitator in the chamber. Theagitator is driven through V belts 22 by an electric motor 2 5. Openingsare provided in the bottom of the chamber for the discharge of the sand,the position and number of these openings depend ing on the type ofcores or moulds to be made.

The blowing chamber has not been illustrated or described in detail asit is of known type.

The table 2 which supports the core-box or mould to be filled is mountedon the upper end of a ram 25 working in a vertical cylinder 26 whichcommunicates with a pressure chamber 21 through a passage 28 controlledby a springloaded valve 29 as shown in Figure 4. This valve is urgedtowards its seating 30 by a spring 3! bearing against the bottom of thevalve head but the valve is normally held open by a springloaded plunger32 which enters the upper end of the chamber 2? and bears on the stem ofthe valve. v

Theplunger is guided in an extension 33 of a closure 34 bolted to andclosing the upper end of the chamber 27, and a head on the upper end ofthe plunger carries a cup leather 35 working in an enlarged bore 35 inthe closure. The cup leather is held between the head and a disc 31,

and springs 33 bearing on the disc normally hold the plunger in itslowermost position in which it holds the valve 29 open. The bore 36below the cup leather is in communication with the interior of thechamber 2'! through one or more passages 39.

The chamber 21 is partially filled with oil and means are provided foradmitting air under pressure into the chamber above the surface of theoil.

When the compressed air is admitted oil is forced from the chamber 21into. the ram cylinder 26 by way of the valve 29 and passage 28, and theram 25 and table 24 are raised to clamp a core-box or mould which hasbeen placed on the table against the bottom of the blowing chamber l9.When the pressure in the chamber 2? reaches a predetermined value thespring-loaded plunger 32 is forced upwardly against the action of thesprings 32 by the pressure acting on the plunger and on the underside ofthe head. The valve 29 then closes and seals the ram cylinder so thatthe table is locked in position.

To intensify the upward pressure on the table the upper part 46 of thetable is allowed a limited vertical movement relative to the lower partand there is arranged between them a flexible diaphragm 6| ofsubstantially the same area as the table. The periphery of the diaphragmis clamped between the lower part of the table and a clamping ring 42.The relative vertical movement of the upper part 46 of the table islimited by a sleeve 43 which surrounds the table. This sleeve has anengagement with a shoulder on the part 46 and near its lower end thesleeve carries an internal ring 44 between which and the lower part ofthe table there is a small ver-- tical clearance.

After the valve 29 closes air under pressure is admitted below thediaphragm 4i and owing to the relatively large area of the diaphragm theair applies a very high upward pressure to the table and so to thecore-box or mould.

The various operations are controlled by a series of valves and switcheswhich are mounted in vertical alignment in a casing 45 mounted at oneside of the machine. Figures 5 and 6 show the arrangement of the controlmechanism.

A main supply pipe 46 leads air under pressure from a compressor orother source to a central bore 41 in a hollow pillar 48 having fouroutlets controlled by valves 49, 50, 5| and 52. A parallel bore 53 inthe pillar is also in communication with the valves and has connected toit an exhaust pipe 54 leading to atmosphere. One valve controls thesupply of air to the blowing chamber 1 9 through a pipe 55, anothercontrols the supply of air through a pipe 56 to the air cylinder 2| forthe shutter 26, a third valve controls the supply of air through a pipe5! to the space below the diaphragm 4!, and the fourth valve controlsthe supply of air through a pipe 58 to the pressure chamber 21.

Below the valves are two electric switches 59 and 60 controllingrespectively the energising of the motor I6 for driving the sandcontainer and the motor 23 for driving the agitator in the blowingchamber.

The valves and switches are selectively actuated in the required orderby cams 6| on a rotatable vertical spindle 62 provided at its upper endwith a handle 63. The cams actuate the valves and switches throughpivoted rockers 64 carrying rollers for engagement with the cams and thevalves and switches to reduce friction.

The sequence of operations when the handle 63 is rotated step by step inone direction is as follows:

The motor I6 is switched on to rotate the sand container 12, and air isadmitted to the cylinder 2| which opens the shutter 26 and allows sandto pass into the blowing chamber. The container is then stopped and theshutter is closed.

Air is admitted into the pressure chamber 21 to force oil out of thatchamber into the ram cyl nder and raise the table 24 to clamp thecorebox or mould against the bottom of the blowing chamber l9. When apredetermined pressure has been reached the plunger 32 is raised and 4the valve 29 closes, and air is then admitted under the diaphragm 4| tointensify the upward pressure on the core-box or mould.

Next air under pressure is admitted to the blowing chamber and theagitator in the chamher is driven. After a predetermined time intervalsufiicient to allow the core-box or mould to be filled, the air is cutoil from the blowing chamber and the agitator is stopped and the chamberis connected to exhaust to release the pressure.

The air feed to the space under the diaphragm 4| is then cut off andthis space is connected to exhaust and the air supply to the pressurechamber 27 is cut off and that chamber is connected to exhaust. Thepressure on the spring-loaded plunger 32 is thus relieved and theplunger opens the valve 29 between the ram cylinder and the pressurechamber so that oil can return from the ram cylinder to the pressurechamber and the ram and table can descend under gravity to allow thefilled core-box or mould to be removed.

Preferably at the same time as the pressure in the pressure chamber 2'!is relieved the sand container is set in motion again and the shutter isopened to refill the blowing chamber, and the cycle of operations startsagain.

To speed up production sliding carriages 65, 66 may be arranged onopposite sides of the table of the machine and at the same level as thetable in its lowered position, each carriage having wheels running onrails spaced apart at a distance greater than the width of the table. Acore-box or mould is prepared on one carriage and the carriage with thecore-box or mould on it is slid over the table which lifts the carriageoff into rails and takes it up with the core-box or mould. Meanwhileanother core-box or mould is being prepared on the other carriage, andafter the first core-box or mould has been filled and the table hasreturned to its lowered position the first carriage is slid off to oneside of the table and the second is slid on from the other side.

I claim:

1. A machine of the type set forth for making foundry cores and mouldscomprising a sand container, a blowing chamber below said container,means for feeding sand intermittently from said container into saidchamber, a table below said chamber for supporting a mould to be filled,an hydraulic ram on which said table is mounted and which is adapted toraise the table vertically to clamp the mould against the bottom of theblowing chamber, a passage connecting the lower end of the ram cylinderand a pressure chamber containing oil, means for admitting air underpressure to said chamber above the oil to force the oil into the ramcylinder, a springloaded valve in said passage, a pressure-responsivedevice within the chamber operatively connected with said valve, springmeans acting on said device to normally move the latter to a position toopen said valve, said device bein subjected to the pressure within thechamber and movable when a predetermined pressure is reached therein toallow said valve to close, and pneumatic means associated with saidtable for intensifying the clamping pressure on the mould when the valveis closed.

2. A machine of the type set forth for making foundry cores and mouldscomprising a sand container, a blowing chamber below said container,means for feeding sand intermittently from said container into saidchamber, means for feeding air under pressure into said chamber, a tablebelow said chamber for supporting a mould to be filled, said tablehaving a relatively movable upper part to receive the mould, a flexiblediaphragm substantially co-extensive with the table between the tableand the said relatively movable mouldreceiving part, an hydraulic ramcarrying said table and working; in a vertical cylinder, a pressurechamber containing oil adjacent to the rain cylin a passage connectingthe bottom of the ram cylinder and the pressure chamber, a spring-loadedvalve in said passage, means for admitting air under pressure to saidpressure chamber to force oil from the chamber through said passage intothe rain cylinder to raise the ram and clamp the mould against thebottom of the blowing chamber, a pressureresponsive device within thepressure chamber operatively connected with said valve, spring meansacting on said device to move the latter to a position to maintain saidvalve normally open, said device being subjected to the pressure withinthe pressure chamber and movable when a predetermined pressure isreached therein to allow said valve to close, and means for subsequentlyadmitting air under the diaphragm to intensify the clamping pressure onthe mould.

3. A machine of the type set forth for making foundry cores and mouldscomprising a sand container rotatable about a vertical axis, electricalmeans for driving said container intermittently, a blowing chamberarranged below said container, pneumatically operated means for feedingsand intermittently from said container into said blowing chamber, amould-supporting table below said blowing chamber, an hydraulic ram onwhich said table is mounted for moving said table vertically to clamp amould against the bottom of the blowing chamber, pneumatic means forforcing oil from a pressure chamber into the ram cylinder, meansincluding a device within the pressure chamber and subjected at alltimes to the pressure therein for closing the communication between thepressure chamber and the ram cylinder when a predetermined pressure isreached, pneumatic means associated with said table for intensifying theclamping pressure on the mould, grouped valves and switches forcontrolling the supply of compressed air and current to initiate thevarious operations of the machine, and a rotatable spindle carrying camsfor actuating said valves and switches automatically in the correctsequence.

4. A machine of the type set forth for making foundry cores and mouldscomprising a cylindrical sand container rotatable about a vertical axis,means for rotatin said container intermittently, a fixed plate overwhich said container works, blowing chamber arranged below said plate,an opening in said plate leading into said blowing chamber, a pivotedshutter for covering and uncovering said opening to control the deliveryof sand from container int said blowing chniber, pneumatic means foroperating said shut r, a supporting table below said blowing chamber, anhydraulic ram on which said table is mounted for moving said tablevertically to clamp a mould against the bottom of the blowing chamber,pneumatic means for forcing oil from a pressure chamber into the ramcylinder,

means including a device within the pressure chamber and subjected atall times to the pressure therein for closin the communication betweenthe pressure chamber and the ram cylinder when a predetermined pressureis reached, pneumatic means associated with said table and moving a partof said table relative to another part to intensify the clampingpressure on the mould during filling, and a rotary control forcontrolling each of the operations of the machine and for ensuringautomatically that these operations take place in the correct sequence.

HEINRICH SCHULTE I-IERBRUGGEN.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 819,883 Hewlett May 8, 19061,030,326 Peterson June 25, 1912 1,563,156 Burman Nov. 24, 19251,781,168 Dollin Nov. 11, 1930 1,801,654 Blood Apr. 21, 1931 1,866,301Goodlin July 5, 1932 1,940,063 Sherman Dec. 19, 1933 2,088,123 TomanJuly 27, 1937 2,192,133 Hagemeyer Feb. 27, 1940 2,300,148 Gilliland Oct.27, 1942 2,409,330 Wood et a1 Oct. 15, 1946

